Laser types and wavelengths
Laser wavelength is expressed in nanometres (nm), not as a needle length or a depth of treatment. Familiar examples include CO₂ at 10,600 nm, Er:YAG at 2,940 nm, Nd:YAG at 1,064 nm and alexandrite at 755 nm. These examples describe different laser systems; they are not a recommendation for your skin or a complete list.
CO₂ / carbon dioxide laser
CO₂ systems at 10,600 nm are established resurfacing examples. Full-field and fractional treatment differ in delivery. The name alone does not determine the intensity or recovery.
Er:YAG / erbium:YAG laser
Er:YAG at 2,940 nm is a resurfacing example. It is different from erbium:glass systems. The practitioner should identify the exact laser, delivery mode and planned tissue effect.
Nd:YAG / neodymium:YAG laser
Nd:YAG systems commonly use 1,064 nm; some also generate 532 nm light through frequency doubling. Long-pulsed, Q-switched and picosecond applications have different targets and treatment plans.
Alexandrite laser
Alexandrite at 755 nm is one laser family. The exact pulse mode, target, skin tone and cooling plan matter; the wavelength is not a universal suitability rating.
Diode lasers
Diode describes a semiconductor laser family with different wavelengths. A familiar hair-reduction wavelength such as 808 nm does not define every diode device or every application.
Fractional, full-field and pulse modes
Fractional describes a pattern of treatment zones and can be ablative or non-ablative. Q-switched, picosecond and long-pulsed describe aspects of pulse delivery. Picosecond systems can also be Q-switched; these labels are not mutually exclusive laser ingredients.
Questions to bring
What laser, wavelength and treatment mode are you proposing? What is the target: pigment, vessels, hair or skin texture? Why is this approach appropriate for my skin tone, recent tan and history? What eye protection, aftercare and expected healing are needed? How does the plan address pigment change, burns and scarring?
Evidence and scope
Regulator device records verify technical examples for specific systems. They do not make every use of that wavelength appropriate or demonstrate comparative superiority.
Read the original sources
Sources describe specific products, studies or countries. They do not establish approval everywhere.
General education. Your clinician can assess your individual suitability. Rules depend on the treatment country; FDA references concern the United States. External sources may be in another language.